Is that possible to use a tag to identify some shops that are part of a local organization?

I'm working for a local organization that explains to storekeepers that some customers would like to buy products without packaging (bulk products) to reduce their amount of waste generated. The organization certifies the shops once the storekeeper understands this purpose and accepts that customers buy some products (meat, vegetables...) with their own wrapping solutions (could be a jar, a re-used paper bag...).

Do you think it would be best to use a local tag like <organization_name>_certified or a more generic tag like: customer_wrapping_solutions_accepted?

For me something generic like customer_wrapping_solutions_accepted=yes seem to be the better way to go. Who should know all the possibly thousands of local organizations who might issue such "certificates". Plus it has a slight touch of being spam to add some organization's name to shops.

I just do not know what a good tag key might be.

Some ideas:

customer_wrapping_solutions_accepted=yes

bring_your_own_packaging=yes

bring_your_own_containers=yes

byop=yes

bulk_buy=yes

zero_waste_buy=yes

After some searching with taginfo I also found keys which are already in use:

I don't think bulk purchase is right: from the description the quanity of goods might be small, just not packaged. Whatever tag is used, I'd suggest suitable_tag_scheme="Name of Organisation" as a way to allow for a variety of schemes.

@SK53 from what I understood, bulk_purchase should mean this. As said on the wiki talk page over there, I think, too, that the key might be misleading because of the two meanings in English. But do we want to invent a new tag now? We already have a established base of 88.

I do not understand your proposed tag, could you detail on that? An example? Maybe write an own "answer" for this.